There is a few problems with using a CF card adapter in the 150. I don't know why. Though this should act as a normal hard drive. There is a 44 pin version. I will find that.

EDIT: If I do get a 44 Pin version, will I be able to initialize it with the built in drive setup? Would there be a utility I could squeeze onto the PowerBook 150's Utilites floppy (After deleting everything not related to booting)?